遍历iOS核心数据的单个实体
我有一个实体“testData”,它有三个属性:时间、节拍、速率。我需要每次遍历“time”属性,并将每个属性对应的beat和rate值存储在NSMutablearray中遍历iOS核心数据的单个实体,ios,core-data,entity,traversal,Ios,Core Data,Entity,Traversal,我有一个实体“testData”,它有三个属性:时间、节拍、速率。我需要每次遍历“time”属性,并将每个属性对应的beat和rate值存储在NSMutablearray中 NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest]
NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
NSManagedObject *newManagedObject = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
[newManagedObject setValue:[x] forKey:@"timeStamp"];
[newManagedObject setValue:[y] forKey:@"beat"];
[newManagedObject setValue:[z] forKey:@"rate"];
// Save the context.
NSError *error = nil;
if (![context save:&error]) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
如果我了解您想要做什么: 对该实体执行FetchRequest(无谓词)并将结果放入NSArray 对返回的数组执行ForIn,并将所需的对象(节拍和速率)添加到相应的nsmutableArray中 另外-您可能想查看(一个使处理核心数据更有趣的开源库:)什么是“遍历时间属性”?您的代码用于创建新实体,您的问题是关于获取和解析现有实体。你的问题是什么?